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  <title>Document</title>
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    .title {
      color: red;
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<body>
  
  <!-- <h1 属性名="属性值">我是标题</h1> -->
  <h1 class="title" id="abc">我是标题</h1>
  <h1>我也是标题</h1>

  <!-- 超链接元素 -->
  <a class="baidu" href="http://www.baidu.com">百度一下</a>

  <img class="">

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